1 pound fresh yellowfin tuna, cut into about 1/2-inch dice
3 tablespoons lime juice
Sea salt
1 cup fresh coconut milk
1/4 cup peeled and 2-inch-diced carrots
1/4 cup peeled, seeded and 2-inch-diced cucumber
2 tomatoes peeled, seeded and cut into 2-inch dice, or cherry tomatoes cut in half
Freshly ground pepper
1 tablespoon finely chopped scallion